U.S. patent application number 16/067926 was filed with the patent office on 2020-08-27 for 3-d printing process for forming flat panel array antenna.
The applicant listed for this patent is CommScope Technologies LLC. Invention is credited to Claudio Biancotto, Ian Thomas Renilson, David J. Walker.
Application Number | 20200274252 16/067926 |
Document ID | / |
Family ID | 1000004844670 |
Filed Date | 2020-08-27 |
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United States Patent
Application |
20200274252 |
Kind Code |
A1 |
Renilson; Ian Thomas ; et
al. |
August 27, 2020 |
3-D PRINTING PROCESS FOR FORMING FLAT PANEL ARRAY ANTENNA
Abstract
A method of forming a flat panel array antenna includes the
steps of: (a) providing a digitized design for a flat panel array,
the flat panel array comprising a plurality of geometric features
that vary in area along a thickness dimension of the flat panel
array; (b) subdividing the digitized design into a plurality of
thin strata stacked in the thickness dimension; (c) forming a thin
layer of material corresponding to one of the thin strata; (d)
fixing the thin layer of material; and (e) repeating steps (c) and
(d) to form a flat panel array.
Inventors: |
Renilson; Ian Thomas; (Fife,
GB) ; Biancotto; Claudio; (Edinburgh, GB) ;
Walker; David J.; (Glasgow, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CommScope Technologies LLC |
Hickory |
NC |
US |
|
|
Family ID: |
1000004844670 |
Appl. No.: |
16/067926 |
Filed: |
February 21, 2017 |
PCT Filed: |
February 21, 2017 |
PCT NO: |
PCT/US2017/018644 |
371 Date: |
July 3, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62305881 |
Mar 9, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01Q 21/064 20130101;
H01Q 21/0087 20130101; B33Y 80/00 20141201 |
International
Class: |
H01Q 21/00 20060101
H01Q021/00; H01Q 21/06 20060101 H01Q021/06; B33Y 80/00 20060101
B33Y080/00 |
Claims
1. A method of forming a flat panel array antenna, comprising the
steps of: (a) providing a digitized design for a flat panel array,
the flat panel array comprising a plurality of geometric features
that vary in area along a thickness dimension of the flat panel
array; (b) subdividing the digitized design into a plurality of
thin strata stacked in the thickness dimension; (c) forming a thin
layer of material corresponding to one of the thin strata; (d)
fixing the thin layer of material; and (e) repeating steps (c) and
(d) to form a flat, panel array.
2. The method defined in claim 1, wherein geometric features
include at least one of holes, slots, and undercuts.
3. The method defined in Claim 1, wherein the thin layer of
material comprises a metallic material.
4. The method defined in claim 1, wherein step (d) comprises
heating the thin layer.
5. The method defined in claim 1, further comprising performing
step (c) on a substrate.
6. The method defined in claim 5, wherein the substrate is
configured to serve as a backplate for the flat panel array,
7. The method defined in claim 1, wherein the flat panel array
includes a plurality of distinct flat panel array layers.
8. The method defined in claim 7, wherein the flat panel array
layers include at least one of an input layer, an intermediate
layer, a slot layer, and an output layer.
9. The method defined in claim 7, wherein the fiat panel array
layers include one or more of slots, coupling cavities, power
dividers and radiation horns.
10. A flat panel array formed by the method of claim 1.
11. The flat panel array defined in claim 10, wherein geometric
features include at least one of holes, slots, and undercuts.
12. The flat panel array defined in claim 10, wherein the thin
layer of material comprises a metallic material.
13. The flat panel array defined in claim 10 formed on a
substrate.
14. The flat panel array defined in claim 13, wherein the substrate
is configured to serve as a backplate for the flat panel array.
15. The fiat panel, array defined in claim 10, wherein the flat
panel array includes a plurality of distinct flat panel array
layers.
16. The flat panel array defined in claim 15, wherein the flat
panel array layers include at least one of an input layer, an
intermediate layer, a slot layer, and an output layer.
17. The flat panel array defined in claim 15, wherein the flat
panel array layers include one or more of slots, coupling cavities,
power dividers and radiation horns.
Description
RELATED APPLICATION
[0001] The present application claims priority from and the benefit
of U.S. Provisional Patent Application No. 62/305,881, filed Mar.
9, 2016, the disclosure of which is hereby incorporated herein in
its entirety.
FIELD OF THE INVENTION
[0002] The present application is directed generally to antennas,
and more particularly to flat panel antennas.
BACKGROUND
[0003] Flat panel array antenna technology has not been extensively
applied within the licensed commercial microwave point-to-point or
point-to-multipoint market, where stringent electromagnetic
radiation envelope characteristics consistent with efficient
spectrum management are common. Antenna solutions derived from
traditional reflector antenna configurations such as prime
focus-fed axisymmetric geometries provide high levels of antenna
directivity and gain at relatively low cost. However, the extensive
structure of a reflector dish and associated feed may require
significantly enhanced support structure to withstand wind loads,
which may increase overall costs. Further, the increased size of
reflector antenna assemblies and the support structure required may
be viewed as a visual blight.
[0004] Array antennas typically utilize either printed circuit
technology or waveguide technology. The components of the array
which interface with free space, known as the elements, typically
utilize microstrip geometries, such as patches, dipoles or slots,
or waveguide components such as horns or slots. The various
elements are interconnected by a feed network, so that the
resulting electromagnetic radiation characteristics of the antenna
conform to desired characteristics, such as the antenna beam
pointing direction, directivity, and sidelobe distribution.
[0005] Flat panel arrays may be formed, for example, using
waveguide or printed slot arrays in either resonant or travelling
wave configurations. Resonant configurations typically cannot
achieve the requisite electromagnetic characteristics over the
bandwidths utilized in the terrestrial point-to-point market
sector, while travelling wave arrays typically provide a mainbeam
radiation pattern which moves in angular position with frequency.
Because terrestrial point to point communications generally operate
with Go/Return channels spaced over different parts of the
frequency band being utilized, movement of the mainbeam with
respect to frequency may prevent simultaneous efficient alignment
of the link for both channels.
[0006] U.S. Pat. No. 8,558,746 to Thompson et al. discusses a flat
panel array antenna constructed as a series of different layers.
Shown therein are flat panel arrays that include input,
intermediate and output layers, with some embodiments including one
or more slot layers and one or more additional intermediate layers.
The layers are manufactured separately (typically via machining or
casting) and stacked to form an overall feed network. The
disclosure of this patent is hereby incorporated herein by
reference in its entirety.
SUMMARY
[0007] As a first aspect, embodiments of the invention are directed
to a method of forming a flat panel array antenna, comprising the
steps of: (a) providing a digitized design for a flat panel array,
the flat panel array comprising a plurality of geometric features
that vary in area along a thickness dimension of the flat panel
array; (b) subdividing the digitized design into a plurality of
thin strata stacked in the thickness dimension; (c) forming a thin
layer of material corresponding to one of the thin strata; (d)
fixing the thin layer of material; and (e) repeating steps (c) and
(d) to form a flat panel array.
[0008] As a second aspect, embodiments of the invention are
directed to a flat panel array antenna formed by the process
described above.
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1A is a perspective view of a flat panel array
antenna.
[0010] FIG. 1B is a series of perspective views showing the
construction of a flat panel array antenna.
[0011] FIG. 2 is an exploded perspective view of the flat panel
array antenna of FIG. 1 showing the different layers of the feeding
network.
[0012] FIG. 3 is an enlarged exploded perspective view of the
elements of the layers of the flat panel array antenna of FIG.
2.
[0013] FIGS. 4 and 5 are RF air models associated with the flat
panel array antenna of FIGS. 2 and 3.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0014] The present invention will now be described more fully
hereinafter, in which embodiments of the invention are shown. This
invention may, however, be embodied in different forms and should
not be construed as limited to the embodiments set forth herein.
Rather, these embodiments are provided so that this disclosure will
be thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. In the drawings, like
numbers refer to like elements throughout. Thicknesses and
dimensions of some components may be exaggerated for clarity.
[0015] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0016] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein the expression "and/or" includes any and all
combinations of one or more of the associated listed items.
[0017] In addition, spatially relative terms, such as "under",
"below", "lower", "over", "upper" and the like, may be used herein
for ease of description to describe one element or feature's
relationship to another element(s) or feature(s) as illustrated in
the figures. It will be understood that the spatially relative
terms are intended to encompass different orientations of the
device in use or operation in addition to the orientation depicted
in the figures. The device may be otherwise oriented (rotated 90
degrees or at other orientations) and the spatially relative
descriptors used herein interpreted accordingly.
[0018] Well-known functions or constructions may not be described
in detail for brevity and/or clarity.
[0019] Referring now to the figures, an antenna assembly,
designated broadly at 10, is shown in FIGS. 1A and 1B. The antenna
assembly 10 includes, inter alia, a flat panel array 20 as
described above. As noted, typically flat panel array antennas 20
have been formed in multiple layers via machining or casting.
However, these techniques can present performance issues as well as
high manufacturing and part costs. Machining is typically employed
for prototyping and low volume parts. Complex parts are formed by
conventional machining techniques, whereas simpler layers may be
formed using punched plates. Casting is typically employed for
higher volume parts, but requires a considerable investment in
tooling.
[0020] Other issues may also be presented by machining and casting.
For example, machined parts typically have sharp corners and lack
"draft" angles for holes, edges and the like. In contrast, cast
parts typically have more radiused corners and include some draft
angle, both of which can facilitate removal of the part from the
casting mold. Because the configurations of the machined and cast
parts are slightly different, they can have somewhat different
performance characteristics. As a result, when a flat panel array
is prototyped with machined parts, it may deliver somewhat
different performance than the same flat panel array produced via
casting in production volumes.
[0021] In addition, cast parts will include split lines or weld
lines that are formed when material flows within the mold around a
mold feature to form a hole, slot or the like (which are numerous
in many flat panel array layers). The presence of split lines can
cause loss and energy leakage in the antenna, which can affect
radiation patterns and generate interference with nearby
devices.
[0022] In addition, antennas of a different size and/or frequency
may have different flat panel array layers. As such, separate
casting tools (which are expensive) may be required for each
variety of antenna produced.
[0023] Many of these issues may be addressed via manufacturing flat
panel arrays through the use of a three-dimensional (3D) printing
process. With this technique, the three-dimensional structure of a
substrate (in this instance the entire flat panel array, with all
of its layers) is digitized via computer-aided solid modeling or
the like. The coordinates defining the substrate are then
transferred to a device that uses the digitized data to build the
substrate. Typically, a processor subdivides the three-dimensional
geometry of the substrate into thin "slices" or layers. Based on
these subdivisions, a printer or other application device then
applies thin layers of material sequentially to build the
three-dimensional configuration of the substrate. Some methods melt
or soften, then harden, material to produce the layers, while
others cure liquid materials using different methods to form, then
fix, the layers in place. 3D printing techniques are particularly
useful for items that vary in area along the thickness dimension
(i.e., the dimension that is normal to the thin "slices").
[0024] One such technique involves the use of a selective laser,
which can employed in either selective laser sintering (SLS) or
selective laser melting (SLM). Like other methods of 3D printing,
an object formed with an SLS/SLM machine starts as a computer-aided
design (CAD) file. CAD files are converted to a data format (e.g.,
an .stl format), which can be understood by a 3D printing
apparatus. A powder material, such as a metal or polymer, is
dispersed in a thin layer on top of the build platform inside an
SLS machine. A laser directed by the CAD data pulses down on the
platform, tracing a cross-section of the object onto the powder.
The laser heats the powder either to just below its boiling point
(sintering) or above its melting point (melting), which fuses the
particles in the powder together into a solid form. Once the
initial layer is formed, the platform of the SLS machine drops
usually by less than 0.1 mm exposing a new layer of powder for the
laser to trace and fuse together. This process continues again and
again until the entire object has been formed. When the object is
fully formed, it is left to cool in the machine before being
removed.
[0025] Another 3D printing technique is multi-jet modeling (MJM).
With this technique, multiple printer heads apply layers of
structural material to form the substrate. Often, layers of a
support material are also applied in areas where no material is
present to serve as a support structure. The structural material is
cured, then the support material is removed. As an example, the
structural material may comprise a curable polymeric resin or a
fusable metal, and the support material may comprise a paraffin wax
that can be easily melted and removed.
[0026] Another such technique is fused deposition modeling (FDM).
Like MJM, this technique also works on an "additive" principle by
laying down material in layers. A plastic filament or metal wire is
unwound from a coil and supplies material to an extrusion nozzle
which can turn the flow on and off. The nozzle is heated to melt
the material and can be moved in both horizontal and vertical
directions by a numerically controlled mechanism, directly
controlled by a computer-aided manufacturing (CAM) software
package. The model or part is produced by extruding small beads of
material to form layers; typically, the material hardens
immediately after extrusion from the nozzle, such that no support
structure is employed.
[0027] Still other techniques of additive manufacturing processes
include stereolithography (which employs light-curable material and
a precise light source), laminated object manufacturing, metal arc
welding, wire feed additive manufacturing, binder jetting, electron
beam melting, blown powder, metal and binder, welding and other
emerging technologies.
[0028] Irrespective of which 3D printing technique is employed,
there are multiple potential advantages for the production of a
flat panel array. First, the internal feeding networks and complex
RF output layer profiles (including undercuts) of the flat panel
array can be formed in one piece, rather than as separate layers,
which reduces time and eliminates the cost of multiple tools.
Second, parts produced during the development from initial
prototype/low volume production to high volume production should
have the same RF profile, rather than the slightly different
profile based on the differences between machined parts and cast
parts. Consequently, the development may be reduced to merely
mechanical issues such as flatness, alignment and clamping, without
electrical issues resulting from the differences in machined and
cast panels. These mechanical issues are typically the same for
each frequency, so the development time, effort and cost to convert
a full range of antennas from prototype/ low volume production to
high volume production may be considerably less.
[0029] Referring again to the figures, FIGS. 2 and 3 illustrate an
exemplary flat panel array 120. The exemplary flat panel array 120
includes four overlying layers 122, 124, 126, 128, each of which
has a unique geometry. The layers 122, 124, 126, 128 are designed
such that, when combined, they form a feed network for distributing
RF signals from a central output; As examples, the layers 122, 124,
126, 128 may include features such as holes, slots, ridges, sloping
surfaces, and the like as part of the geometry of the overall flat
panel array 120. These features tend to vary along the thickness
dimension of the flat panel array 120. For example, the layers may
comprise an input layer 122 with power dividers 123, an
intermediate layer 124 with coupling cavities 125, a slot layer 126
with slots 127, and an output layer 128 with horn radiators 129
(see FIGS. 2 and 3). The layers are also depicted in the air models
associated with the flat panel array 120 illustrated in FIGS. 4 and
5. Those of skill in this art will appreciate that other types of
features may be present as desired (some such features are
described in U.S. Pat. No. 8,558,746, supra).
[0030] As will be understood by those of skill in this art, the
flat panel array 120, including the various layers 122, 124, 126,
128, may be formed in a single operation via one or more of the 3D
printing techniques discussed above. As noted, 3D printing builds
structures by forming thin strata or "slices" of the structure one
at a time until the entire structure is completed. In the case of
the flat panel array 120, the different layers 122, 124, 126, 128
can be formed in a single continuous operation, which includes the
formation of voids, hollows, closed channels, ridges, undercuts,
and the like within the overall structure that would not be
possible to form with a machining or casting operation.
[0031] Those skilled in this art will appreciate that the
configuration of the flat panel array 120 is exemplary only. Other
configurations are also possible, including flat panel arrays that
include more or fewer layers than the four layers 122, 124, 126,
128 shown herein, and/or flat panel arrays that have different
contours and features than those shown herein.
[0032] In addition, some layers may be formed via other techniques.
For example, rather than employing a build platform as described
above, the 3D printing may be performed by printing onto a
substrate that is geometrically simple that can then form the
structural backplate of the antenna. This substrate could be formed
from a machined plate (for prototype/ low volume production), or a
cast plate (for high volume production), with these operations
being more cost-effective due to the simplified geometry of the
backplate.
[0033] As another example, the output layer 128, which includes the
horn radiators 129, may be formed via 3D printing, with the
remaining layers 122, 124, 126 formed via casting. This
configuration takes advantage of the benefits of 3D printing for
the output layer 128, but enables casting operations (which can
produce a less "lossy" surface) to be employed for the other
layers, for which surface finish can be more important.
[0034] It is also contemplated that, although 3D printing of metals
has been the focus of much of the discussion above, 3D printed
plastic parts with subsequently metalized surfaces may also be
employed.
[0035] Those skilled in this art will further appreciate that 3D
printing can also be used to form external shapes that can be used
to improve RF performance of the antenna, such as backlobe and
sidelobe EM suppression devices (see, e.g., U.S. Patent Publication
Nos. 2015/0116184 and 2013/0082896, the disclosures of which are
hereby incorporated herein in their entirety). 3D printing may also
be employed to form other components used in antennas, such as
transitions and polarizers as shown in FIG. 1B, orthomode
transducers (OMTs), couplers, diplexers, filters and the like.
[0036] The foregoing is illustrative of the present invention and
is not to be construed as limiting thereof Although exemplary
embodiments of this invention have been described, those skilled in
the art will readily appreciate that many modifications are
possible in the exemplary embodiments without materially departing
from the novel teachings and advantages of this invention.
Accordingly, all such modifications are intended to be included
within the scope of this invention as defined in the claims. The
invention is defined by the following claims, with equivalents of
the claims to be included therein.
* * * * *